The crystal of the title compound, 5-diazo-4-ethoxycarbonyl-3-methylthio pyrazole, has been prepared and determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 29.174(...The crystal of the title compound, 5-diazo-4-ethoxycarbonyl-3-methylthio pyrazole, has been prepared and determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 29.174(8), b = 4.7592(12), c = 15.956(4) ? b = 117.632(4), C7H8N4O2S, Mr = 212.23, V = 1962.7(9) ?, Z = 8, Dx = 1.436 g/cm3, S = 1.000, m(MoKa) = 0.31 mm-1, T = 298(2) K, F(000) = 880, R = 0.0658 and wR = 0.1741 for 1091 independent reflections with I ≥ 2s(I). The crystal of the title compound is formed with p-p interactions through electrostatic attractions. Moreover, no HSO4- exists in the crystal structure. Therefore, only diazo pyrazole was obtained rather than either diazonium salt of the corresponding pyrazole or diazoaminopyrazole when 5-amino-4-ethoxycarbonyl-3-methylthio pyrazole was diazotized with sodium nitrite, catalyzed by sulfuric acid at 0 ℃.展开更多
The reactions of 5,5＇-bis（2-acylphenyl）diazo-dipyrromethane （H2L） with CuSO4 and NiCl2 resulted in the formation of corresponding mononuclear coordination complexes 2 （CuL） and 3 （NIL）. The crystal of complex...The reactions of 5,5＇-bis（2-acylphenyl）diazo-dipyrromethane （H2L） with CuSO4 and NiCl2 resulted in the formation of corresponding mononuclear coordination complexes 2 （CuL） and 3 （NIL）. The crystal of complex 2 is of monoclinic system, space group P21 with a = 10.040（5）, b = 11.900（5）, c = 11.170（5） A, β = 93.057（8）°, V = 1332.8（2） A3, Z = 2, C29H28N602Cu, Mr = 556.11, Dc = 1.386 g/cm, F（000） = 578 and/z（MoKa） = 0.857 mm^-1. The crystal of complex 3 belongs to the monoclinic system, space group P21/n with a = 12.0445（6）, b = 17.2101（8）, c = 16.3304（6） A, β = 128.407（2）°, V = 2654.6（2） A3, Z = 4, C29H28N6O2Ni, Mr= 551.28, Dc= 1.380 g/cm, F（000） = 1152 and μ（MoKa） = 0.770 mm^-1. In both complexes, the metal ions are in square-planar geometry by coordinating to two azo N atoms and two deprotonated pyrrole N atoms. Intramolecular Cu…O=C in complex 2 and intermolecular Ni…O=C in complex 3 were found. The UV-Vis spectra and thermal stability of complexes 2 and 3 were also studied.展开更多
A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity a...A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity and significant synthetic applications.This process involves a novel rhodium-catalyzed olefination of diazo compounds,followed by annulation with vinyl azides.This method is compatible with a broad range of substrates and affords moderate to good yields under mild reaction conditions.展开更多
A novel compound 3-nitro-4-diazo-5-oxypyrazole was synthesized by the nitration of 4-amino-3,5-dinitropyrazole using nitrification agents of fuming nitric acid and trifluoroacetic anhydride. The compound was purified ...A novel compound 3-nitro-4-diazo-5-oxypyrazole was synthesized by the nitration of 4-amino-3,5-dinitropyrazole using nitrification agents of fuming nitric acid and trifluoroacetic anhydride. The compound was purified by column chromatography and characterized by IR, NMR, MS and elemental analysis. Two different single crystals obtained by culturing with ethyl acetate as a solvent were measured by X-ray single-crystal diffractometer. The molecular weight of C3HN5O3 is 155.09 and the two crystals belong to monoclinic system, space groups P21/n and P21/c. For 1： a = 5.5007（2）, b = 9.0691（4）, c = 11.4158（4） A, β = 92.710°, V = 568.85 A3, Z = 4, Dc = 1.811 g/cm3, μ = 0.162 mm-1, F（000） = 312 and the final deviation factor is 0.0213. Crystals 1 and 2 have similar unit cell parameters, except that a = 10.1828（12）, b = 5.5925（6）, c = 10.5574（10） A and β = 108.330（4）° in crystal 2. The thermal behavior of the compound was studied by TG-DSC and melting endothermic peak and decomposition exothermic peak are at 425.7 and 534.5 K in DSC curve. The activation energy and pre-exponential factor of the exothermic decomposition reaction of the title compound obtained by Kissinger method and Flynn-Wall-Ozawa method are 50.38 k J/mol, 4.59 × 1022 s^（-1） and 55.89 k J/mol.展开更多
A new azopyrrole compound, 1, has been synthesized and characterized. The crystal of 1 is of monoclinic system, space group P21/c with a = 8.7167（9）, b = 17.5929（19）, c = 12.8096（15） ？, β = 97.565（2）o, V = 1...A new azopyrrole compound, 1, has been synthesized and characterized. The crystal of 1 is of monoclinic system, space group P21/c with a = 8.7167（9）, b = 17.5929（19）, c = 12.8096（15） ？, β = 97.565（2）o, V = 1947.3（4） ^3, Z = 4, C（20）H（26）N4O2, Mr = 354.45, Dc = 1.209 g/cm^3, F（000） = 760 and μ（Mo Kα） = 0.080 mm^-1. In the crystal, 1 binds one methanol molecule through N–H…O, O–H…O and O–H…π interactions. UV-Vis titration and 1H NMR titration studies reveal that compound 1 can selectively detect fluoride ion in the DMSO solution.展开更多
Given the widespread applications of fluorinated substances in pharmaceuticals,biology,and materials,the development of fluorine-containing building blocks remains an important topic in organic chemistry.In the repert...Given the widespread applications of fluorinated substances in pharmaceuticals,biology,and materials,the development of fluorine-containing building blocks remains an important topic in organic chemistry.In the repertoire of fluorinated diazo compounds,research on tri-and difluorodiazoethane is well-established,but the lack of synthetic methods has left studies related to monofluorodiazoethane as an unexplored territory.In our current work,the taming of the smallest monofluorodiazoethane reagent was realized using two phenylsulfonyl mask groups.This newly synthesized diazo reagent displayed intriguing reactivity patterns:the reaction with aryldiazonium salts gave monofluoromethyl tetrazoles,whereas its reactivity with alkynes and alkenes furnished monofluoromethyl isoxazoles and dihydro-isoxazoles.Furthermore,the removal of the masking groups provided access to a wide range of monofluoromethyl-functionalized heterocycles.展开更多
A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kind...A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,10-phenanthrenes.Notably,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic system.The reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.展开更多
A copper-catalyzed[5+1]cycloaddition reaction of terminal alkynes with diazo esters for the rapid construction of protected naphthalen-1(2H)-one derivatives in moderate to good yields has been disclosed along with goo...A copper-catalyzed[5+1]cycloaddition reaction of terminal alkynes with diazo esters for the rapid construction of protected naphthalen-1(2H)-one derivatives in moderate to good yields has been disclosed along with good functional group compatibility and a broad substrate scope.The mechanistic investigations reveal that this tandem cyclization process proceeds through a Cu(I)-catalyzed coupling of terminal alkyne with diazoacetate,a 1,5-H shift process and a thermally induced pericyclic reaction via an allene intermediate.The synthetic utility and the further transformations of the obtained cycloadduct to naphthalenone,naphthol and dihydronaphthol have been also presented in this paper.展开更多
An efficient chlorination reaction of in situ generated(β-diazo-α,α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions.The re...An efficient chlorination reaction of in situ generated(β-diazo-α,α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions.The reaction does not need any catalyst and tolerates a wide scope of substrates,which affords the(β-chlorodifluoroethyl)phosphonate products in good to excellent yields.This reaction represents the first example of the halogenation of difluoroalkyl diazo compounds,and also provides an easy way for the synthesis of difluoromethylenephosphonate-containing compounds.展开更多
Phosphine-relayed olefination and aza-Wittig reactions of readily available aldehydes with 2,2,2-trifluorodiazoethane （CF3CHN2） have been realized. This protocol enables the facile construction of a series of triflu...Phosphine-relayed olefination and aza-Wittig reactions of readily available aldehydes with 2,2,2-trifluorodiazoethane （CF3CHN2） have been realized. This protocol enables the facile construction of a series of trifluoromethylated alkenes and hydrazones in good to high yield under mild conditions.展开更多
Diazo compounds are generally used as carbene precursors. Traditionally, dirhodium, copper and iron catalysts were used to decompose diazo compounds to form the key metal carbene intermediates. Recently, the gold cata...Diazo compounds are generally used as carbene precursors. Traditionally, dirhodium, copper and iron catalysts were used to decompose diazo compounds to form the key metal carbene intermediates. Recently, the gold catalysts have been developed as a unique type of metal catalyst to decompose diazo compounds. The derived gold carbene showed much different characters comparing with other transition metal carbenes. They could go through a series of cycloaddition, insertion and coupling reactions. Here, the recent progress of the gold carbene chemistry from diazo compounds was reviewed, including the scope of reactions,mechanism and synthetic applications.展开更多
A silver-catalyzed three-component coupling reaction of carbon dioxide, amines and α-diazoesters has been developed for the first time. The novel reaction provides an efficient and practical methodology for the synth...A silver-catalyzed three-component coupling reaction of carbon dioxide, amines and α-diazoesters has been developed for the first time. The novel reaction provides an efficient and practical methodology for the synthesis of a wide range of new α-carbamoyloxy esters, which are difficult to prepare by existing methods. The advantages of the method include the use of readily available starting materials, simple catalytic system, good atom economy and high functional group tolerance.展开更多
A novel generation of oxazole vlide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to...A novel generation of oxazole vlide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.展开更多
The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.He...The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.Here we demonstrate that a silver-catalyzed[3+2]cycloaddition reaction of dicyanoalkenes with trifluorodiazoethane(CF_(3)CHN2)could render a facile construction of a unique category of pyrazoles that are simultaneously adorned by trifluoromethyl and cyano groups.Changing the location pattern of the cyano group in starting dicyanoalkene material allows regiodivergent access to two series of previously elusive trifluoromethyl cyanopyrazoles with an exquisite level of regiocontrol.Thus,this method could be applied in the preparation of cyano-analogues of CF_(3)-containing drugs(Celecoxib)and agrochemicals(Penthiopyrad and Fluazolate).Notably,several cyano-analogues of Celecoxib demonstrate enhanced inhibitory activity towards cyclooxygenase-2(COX-2),thereby laying a good foundation for developing new lead-based antiinflammatory agents.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20172031) the Research Fund for the Doctoral Program of High Education,China
文摘The crystal of the title compound, 5-diazo-4-ethoxycarbonyl-3-methylthio pyrazole, has been prepared and determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 29.174(8), b = 4.7592(12), c = 15.956(4) ? b = 117.632(4), C7H8N4O2S, Mr = 212.23, V = 1962.7(9) ?, Z = 8, Dx = 1.436 g/cm3, S = 1.000, m(MoKa) = 0.31 mm-1, T = 298(2) K, F(000) = 880, R = 0.0658 and wR = 0.1741 for 1091 independent reflections with I ≥ 2s(I). The crystal of the title compound is formed with p-p interactions through electrostatic attractions. Moreover, no HSO4- exists in the crystal structure. Therefore, only diazo pyrazole was obtained rather than either diazonium salt of the corresponding pyrazole or diazoaminopyrazole when 5-amino-4-ethoxycarbonyl-3-methylthio pyrazole was diazotized with sodium nitrite, catalyzed by sulfuric acid at 0 ℃.
基金supported by the National Natural Science Foundation of China(NSFC No.21172174)Program of Study Abroad for Young Scholar sponsored by Tianjin Municipal Education Commission
文摘The reactions of 5,5＇-bis（2-acylphenyl）diazo-dipyrromethane （H2L） with CuSO4 and NiCl2 resulted in the formation of corresponding mononuclear coordination complexes 2 （CuL） and 3 （NIL）. The crystal of complex 2 is of monoclinic system, space group P21 with a = 10.040（5）, b = 11.900（5）, c = 11.170（5） A, β = 93.057（8）°, V = 1332.8（2） A3, Z = 2, C29H28N602Cu, Mr = 556.11, Dc = 1.386 g/cm, F（000） = 578 and/z（MoKa） = 0.857 mm^-1. The crystal of complex 3 belongs to the monoclinic system, space group P21/n with a = 12.0445（6）, b = 17.2101（8）, c = 16.3304（6） A, β = 128.407（2）°, V = 2654.6（2） A3, Z = 4, C29H28N6O2Ni, Mr= 551.28, Dc= 1.380 g/cm, F（000） = 1152 and μ（MoKa） = 0.770 mm^-1. In both complexes, the metal ions are in square-planar geometry by coordinating to two azo N atoms and two deprotonated pyrrole N atoms. Intramolecular Cu…O=C in complex 2 and intermolecular Ni…O=C in complex 3 were found. The UV-Vis spectra and thermal stability of complexes 2 and 3 were also studied.
基金supported by the National Natural Science Foundation of China(21572225)~~
文摘A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity and significant synthetic applications.This process involves a novel rhodium-catalyzed olefination of diazo compounds,followed by annulation with vinyl azides.This method is compatible with a broad range of substrates and affords moderate to good yields under mild reaction conditions.
文摘A novel compound 3-nitro-4-diazo-5-oxypyrazole was synthesized by the nitration of 4-amino-3,5-dinitropyrazole using nitrification agents of fuming nitric acid and trifluoroacetic anhydride. The compound was purified by column chromatography and characterized by IR, NMR, MS and elemental analysis. Two different single crystals obtained by culturing with ethyl acetate as a solvent were measured by X-ray single-crystal diffractometer. The molecular weight of C3HN5O3 is 155.09 and the two crystals belong to monoclinic system, space groups P21/n and P21/c. For 1： a = 5.5007（2）, b = 9.0691（4）, c = 11.4158（4） A, β = 92.710°, V = 568.85 A3, Z = 4, Dc = 1.811 g/cm3, μ = 0.162 mm-1, F（000） = 312 and the final deviation factor is 0.0213. Crystals 1 and 2 have similar unit cell parameters, except that a = 10.1828（12）, b = 5.5925（6）, c = 10.5574（10） A and β = 108.330（4）° in crystal 2. The thermal behavior of the compound was studied by TG-DSC and melting endothermic peak and decomposition exothermic peak are at 425.7 and 534.5 K in DSC curve. The activation energy and pre-exponential factor of the exothermic decomposition reaction of the title compound obtained by Kissinger method and Flynn-Wall-Ozawa method are 50.38 k J/mol, 4.59 × 1022 s^（-1） and 55.89 k J/mol.
基金supported by the National Natural Science Foundation of China(No.21172174)
文摘A new azopyrrole compound, 1, has been synthesized and characterized. The crystal of 1 is of monoclinic system, space group P21/c with a = 8.7167（9）, b = 17.5929（19）, c = 12.8096（15） ？, β = 97.565（2）o, V = 1947.3（4） ^3, Z = 4, C（20）H（26）N4O2, Mr = 354.45, Dc = 1.209 g/cm^3, F（000） = 760 and μ（Mo Kα） = 0.080 mm^-1. In the crystal, 1 binds one methanol molecule through N–H…O, O–H…O and O–H…π interactions. UV-Vis titration and 1H NMR titration studies reveal that compound 1 can selectively detect fluoride ion in the DMSO solution.
基金financial support provided by the National Natural Science Foundation of China(NSFC,grant nos.92156025 and 22271212)the National Key Research and Development Program of China(grant nos.2019YFA0905100 and 2021YFF0701700)X.T.thanks the China Postdoctoral Science Foundation(grant no.2022M712350).
文摘Given the widespread applications of fluorinated substances in pharmaceuticals,biology,and materials,the development of fluorine-containing building blocks remains an important topic in organic chemistry.In the repertoire of fluorinated diazo compounds,research on tri-and difluorodiazoethane is well-established,but the lack of synthetic methods has left studies related to monofluorodiazoethane as an unexplored territory.In our current work,the taming of the smallest monofluorodiazoethane reagent was realized using two phenylsulfonyl mask groups.This newly synthesized diazo reagent displayed intriguing reactivity patterns:the reaction with aryldiazonium salts gave monofluoromethyl tetrazoles,whereas its reactivity with alkynes and alkenes furnished monofluoromethyl isoxazoles and dihydro-isoxazoles.Furthermore,the removal of the masking groups provided access to a wide range of monofluoromethyl-functionalized heterocycles.
基金the financial support for this work from the National Key R&D Program of China(2021YFC0864700)the NSFC(Nos.21801066,U1804283 and 82130103)+2 种基金the Central Plains Scholars and Scientists Studio Fund(2018002)the project funded by the Natural Science Foundation of Henan Province(222300420056,222300420204)the China Postdoctoral Science Foundation(2020M682307,2021T140183).
文摘A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,10-phenanthrenes.Notably,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic system.The reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.
基金support from the National Natural Science Foundation of China (Nos.21372250,21121062,21302203,20732008,21772037,21772226,21861132014,91956115,and 22171078).
文摘A copper-catalyzed[5+1]cycloaddition reaction of terminal alkynes with diazo esters for the rapid construction of protected naphthalen-1(2H)-one derivatives in moderate to good yields has been disclosed along with good functional group compatibility and a broad substrate scope.The mechanistic investigations reveal that this tandem cyclization process proceeds through a Cu(I)-catalyzed coupling of terminal alkyne with diazoacetate,a 1,5-H shift process and a thermally induced pericyclic reaction via an allene intermediate.The synthetic utility and the further transformations of the obtained cycloadduct to naphthalenone,naphthol and dihydronaphthol have been also presented in this paper.
基金supports from the National Natural Science Foundation of China (No. 21761132021)German Research Foundation (No. RO362/74–1)Qin Lan project from Jiangsu Province for JLH is also acknowledged
文摘An efficient chlorination reaction of in situ generated(β-diazo-α,α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions.The reaction does not need any catalyst and tolerates a wide scope of substrates,which affords the(β-chlorodifluoroethyl)phosphonate products in good to excellent yields.This reaction represents the first example of the halogenation of difluoroalkyl diazo compounds,and also provides an easy way for the synthesis of difluoromethylenephosphonate-containing compounds.
基金This work was supported financially by the National Natural Science Foundation of China （Nos. 21225208, 21472137, and 21532008）, the National Basic Research Program of China （973 Program： Nos. 2014CB745100, 2015CB856500）, and the Tianjin Municipal Science ＆ Technology Commission （No. 14JCQNJC06200）.
文摘Phosphine-relayed olefination and aza-Wittig reactions of readily available aldehydes with 2,2,2-trifluorodiazoethane （CF3CHN2） have been realized. This protocol enables the facile construction of a series of trifluoromethylated alkenes and hydrazones in good to high yield under mild conditions.
基金supported by the National Natural Science Foundation of China(21372144)China Postdoctoral Science Foundation,the Fundamental Research Funds of Shandong University(2014JC008)the Subject Construction Funds of Shandong University(104.205.2.5)
文摘Diazo compounds are generally used as carbene precursors. Traditionally, dirhodium, copper and iron catalysts were used to decompose diazo compounds to form the key metal carbene intermediates. Recently, the gold catalysts have been developed as a unique type of metal catalyst to decompose diazo compounds. The derived gold carbene showed much different characters comparing with other transition metal carbenes. They could go through a series of cycloaddition, insertion and coupling reactions. Here, the recent progress of the gold carbene chemistry from diazo compounds was reviewed, including the scope of reactions,mechanism and synthetic applications.
文摘A silver-catalyzed three-component coupling reaction of carbon dioxide, amines and α-diazoesters has been developed for the first time. The novel reaction provides an efficient and practical methodology for the synthesis of a wide range of new α-carbamoyloxy esters, which are difficult to prepare by existing methods. The advantages of the method include the use of readily available starting materials, simple catalytic system, good atom economy and high functional group tolerance.
文摘A novel generation of oxazole vlide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.
基金This work is supported by the National Natural Science Foundation of China(grant nos.92156025,21901181,and 21961142015)the National Key Research and Development Program of China(grant nos.2019YFA0905100 and 2021YFF0701700)Tianjin Municipal Science and Technology Commission(grant no.19JCQNJC04700).
文摘The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.Here we demonstrate that a silver-catalyzed[3+2]cycloaddition reaction of dicyanoalkenes with trifluorodiazoethane(CF_(3)CHN2)could render a facile construction of a unique category of pyrazoles that are simultaneously adorned by trifluoromethyl and cyano groups.Changing the location pattern of the cyano group in starting dicyanoalkene material allows regiodivergent access to two series of previously elusive trifluoromethyl cyanopyrazoles with an exquisite level of regiocontrol.Thus,this method could be applied in the preparation of cyano-analogues of CF_(3)-containing drugs(Celecoxib)and agrochemicals(Penthiopyrad and Fluazolate).Notably,several cyano-analogues of Celecoxib demonstrate enhanced inhibitory activity towards cyclooxygenase-2(COX-2),thereby laying a good foundation for developing new lead-based antiinflammatory agents.
